The present invention concerns a portable cleaning device using a dynamic vacuum cleaning system for continuously or intermittently extracting, aspirating and eliminating solid dusts and particles which have settled on a stationary or moving instrument.
It is well known that manually or electrically operated bag system aspirators may be used to remove particles which have settled on fragile optical or micromechanical apparatus. The aspiration is obtained either by using a pear-shaped rubber bag fitted with a tube, or with an electric aspirator which operates continuously. The aspirator may be fitted with a filter meant to collect the solid particles. Such cleaning devices work by creating a vacuum, the applied strength of which is determined both by the power of the source of aspiration and by the distance of the suction nozzle to the surface to be cleaned. The suction will be at its maximum with respect to the surface to be cleaned when the aspirating tube comes into contact with that surface. Such prior art systems create a rough, irregular operating action which is hard to control and which have a tendency to clog. Drawbacks of such systems are that the rough operating action can damage the apparatus to be cleaned. Further, it is very hard to control the aspiration and damage is occasionally done to the apparatus to be cleaned when loose elements are unintentionally withdrawn therefrom. In addition, the aspirator may become blocked, requiring changing of the filters. Still further, an irregular operating action is caused by the bag-type of aspiration or by the violence of electrical aspiration.
The present invention prevents the aforementioned drawbacks. The principle of the present invention is to inject air, another gas, or fluid into an adjustable "venturi" tube which produces a constant suction in a secondary tube used as an aspirator. In use, the apparatus of the present invention provides a gentle vacuum cleaning action. The amount of vacuum may be adjusted to accommodate the particular size particle which is sought to be removed from the dust or particle laden surface. The apparatus of the present invention also makes it possible to avoid damage to the materials to be cleaned and eliminates the problem of blockage or accumulation of dust in the aspiration device. Further, the present apparatus can be made of any metal or molded plastic material, resulting in a low manufacturing cost.
In accordance with the present invention, a vacuum cleaning device is provided. The device comprises a first tube having a source of gas or compressed air connected to one end thereof. The other end of said first tube is joined to an intermediate portion of a second tube and includes a "stem" or deflectable tongue which extends inside the second tube. The stem serves as a means for producing a venturi effect at the junction of the first and second tubes. The gas or compressed air entering the first tube exits from one end of the second tube, the venturi effect producting a vacuum at the other end of the second tube. The second tube may have a cleaning brush attached to the suction end thereof and a mechanical filter attached to the exit end thereof.